C语言C6387报错应该怎么解决呢

Question

给我报错的内容

#define _CRT_SECURE_NO_WARNINGS
#include"changeword.h"
#include<stdio.h>
#include<ctype.h>


int ChangeWordType(char* src, char* dest)
{
    //open a file
    FILE* fp1  = fopen(src,"r") == NULL;
    FILE* fp2 = fopen(dest, "wt+") == NULL;
    char buff = fgetc(fp1);
    while (!feof(fp1))
    {
        fputc(toupper(buff), fp2);
        buff = fgetc(fp1);
    }
    fclose(fp1);
    fclose(fp2);

    return 1;
}

Answer 1

把后面的==NULL删掉啊。写这要干啥？